1. Field of the Invention
The present invention relates, in general, to methods and devices for illuminating inflated devices such as balloons and, more particularly, to an illuminated balloon that uses an externally mounted rear projector to display a pattern or design with moving or animated portions onto an internal surface of the balloon.
2. Relevant Background
Balloons have long been used as novelty toys such as at circuses, fairs, and amusement parks and as decorations at parties. Balloons may be inflated with air or with buoyant gases such as helium to cause them to float upon a string or other tether. Balloons were initially only provided with differing colors but soon were covered with many colorful designs, artwork, and messages. Other advances in balloons include the wide range of materials that are now used for balloons including rubber or latex based balloons to foil balloons formed of metallized nylon or of biaxially-oriented polyethylene terephthalate (boPET) polyester films (e.g., commonly referred to as Mylar®) and other materials.
More recently, balloons have been made even more distinctive with internal illumination. For example, many illuminated balloons have been created that light the interior surfaces of the balloon by placing a light source inside the balloon. The illuminated balloon can then be used as a novelty toy such as for evening events or even used in some cases as a source for area lighting. The light sources are typically battery operated and operate continuously with no power switch and only for the life of the battery. Battery life often has to be balanced against battery weight that has to be overcome by the buoyancy of the balloon and against cost that generally has to be kept quite low to make the illuminated balloon a desirable toy or decoration.
Another difficulty with illuminating internal surfaces of balloons is the amount of heat generated by the light source. Light sources generate heat and contact with the light source may form a hole in the balloon wall or “pop”, the inflated balloon. Recently, light emitting diodes (LEDs) have been utilized as internal light sources, but even LEDs generate heat that can damage a balloon wall. As a result, illuminated balloons have been developed that include support structures that physically house or support the light source and its power source or battery and that attempt to keep the light source positioned apart from the balloon wall. Other support or housing structures for the light source simply attempt to provide a barrier against the heat reaching the balloon wall. In either case, the internal structures have often been relatively complex, have added weight to the balloon, and have increased the overall cost of the illuminated balloon. Additionally, the balloons are typically only useful for the life of the battery.
There remains a demand for novelty balloons (note, any inflated device may be considered a “balloon” for this description) with illuminated internal surfaces. Preferably such illuminated balloons would be inexpensive to manufacture, would be relatively light in structure, and would provide a power source that has extended life or that can be replaced (e.g., a battery that can readily be changed).